1. Field of the Invention
The present invention relates to an image processing apparatus for processing an image based on a reading image of a document, an image forming apparatus having the image processing apparatus, and a computer-readable medium embodying a program for realizing a function of the image processing.
2. Description of Related Art
When a brochure-shaped document is copied to make a brochure, there are different conventional methods. One such method is that the document is copied page by page (double-sided copy if possible). The other method is that an image on two-page spread of the document is copied on one paper and the paper is folded in half at the center and is bound.
In the former method, however, a user must repeat the following operation: a user turns pages of the document, places the document on a copier, and presses a copy button. This operation is extremely troublesome for users. In the latter method, although the copy time is reduced to half as compared with the former method, the copied papers must be folded in half, which is troublesome for users, and odd pages and even pages of the copied papers in a brochure form are deviated from the actual document by one page. Further, since single-sided copying is performed in the latter method, there arises a problem that the copied papers become thicker than the original document.
When copying a so-called saddle stitched brochure, especially which is stapled, it is easy to make a duplicate copy of the brochure because the brochure can relatively easy be disassembled and reassembled. That is, by removing the staples from a binding portion of the brochure, the brochure can be disassembled into sheets, and the separated sheets are copied.
It is conceived that an ideal method for obtaining a saddle stitched brochure from copied papers is to use a saddle stitching machine. The saddle stitching machine, however, has limited uses and is cost-prohibitive. Thus, an image forming apparatus having the saddle stitching machine does not become widespread. Therefore, to form the saddle stitched brochure, it is necessary to stack half-folded papers, to paste creases of the papers to each other, or to staple the papers together. Such operations, however, are troublesome for users. When creases of the half-folded papers are stapled together, there is a problem that strength becomes insufficient and pages are not uniform as compared with a case in which one edges of papers are stapled.
It also seems possible to stitch one edges of papers to form a brochure in which two pages of a document are copied on one face of one paper without folding the papers into two. In this case, however, there arises a problem that the brochure is lacking in continuity in contents corresponding to two pages of the original document, which are copied on one face of one paper, and usability is extremely inferior.
To solve such a problem, Japanese Patent Application Laid-open No. 2003-198832 discloses a technique in which a saddle stitched document is read to obtain images of the document, each of the images is rearranged according to page number for image formation. Japanese Patent Application Laid-open No. 2005-51382 discloses a technique which realizes a division copy in an appropriate page order with respect to various documents and their set state. Japanese Patent Application Laid-open No. 2003-209682 discloses a technique for setting that each page of a document is arranged on either a right page or a left page in two-page spread when bookbinding of pamphlets or the like. This makes it possible to produce copies of the document by laying out a desired page on a specified page without extra work such as insertion of blank pages.
The saddle stitched document is distinguished between first halves and latter halves in page order with respect to a binding portion of the document as a boundary. However, even if any of the above-described techniques is applied, a position of the binding portion of the document cannot be determined and the document cannot be distinguished between first halves and latter halves in page order with respect to the binding portion as a boundary. This makes it difficult to make full use of the features of the saddle stitched document when copying the document. Thus, there is a problem that substantially the same duplicate as the document cannot be obtained.